Eleocharis bolanderi |
Eleocharis ovata |
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Bolander's spikerush |
ovate spike-rush, ovoid spike-rush, ovoid spikesedge, éléocharide ovale |
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Habit | Plants perennial, densely tufted; rhizomes caudexlike, mostly hidden by culms and roots, short, 1.5–3 mm thick, hard, cortex persistent, internodes very short, scales not evident. | |
Culms | subterete, often with to 6 prominent ridges when dry, sulcate, 10–30 cm × 0.3–0.5 mm, firm to rigid, spongy. |
2–35 cm × 0.3–1 mm. |
Leaves | distal leaf sheaths persistent, not splitting, proximally brown, red, or stramineous, distally stramineous, green or reddish, papery, apex sometimes reddish, obtuse, rarely callose, tooth absent. |
apex of distal leaf sheath obtuse to acute, tooth to 0.2 mm. |
Spikelets | ovoid, 3–8 × 2–3 mm, apex acute to obtuse; proximal scale amplexicaulous, entire; subproximal scale with flower; floral scales spreading in fruit, 8–30, 4–5 per mm of rachilla, dark brown to blackish, midrib regions often stramineous or greenish, ovate to lanceolate, 2–3 × 1.5 mm, apex entire, acute, often carinate in distal part of spikelet. |
ovoid, 2–8 × 2–4 mm, apex acute (to blunt); floral scales 25–100+, ca. 10 per mm of rachilla, orange-brown, rarely stramineous, ovate, 1.5–2 × 1 mm, midribs often keeled in distal part of spikelet, apex rounded to subacute. |
Flowers | perianth bristles 3–6, whitish to stramineous, stout to slender, often unequal, from rudimentary to 1/2 of achene length; stamens 3; anthers dark yellow to brown, 0.9–1.4 mm; styles 3-fid. |
perianth bristles present, rarely absent, (5–)6–7, brown, fairly slender, exceeding tubercle; stamens 2(–3); anthers brown, 0.3 mm; styles 2-fid or some 3-fid. |
Achenes | falling with scales, stramineous, rarely dark brown, ovoid to obpyriform, slightly to greatly compressed-trigonous, rarely thickly lenticular, angles prominent or abaxial angle obscure, 0.9–1.2 × 0.65–0.8 mm, apex narrowly to broadly truncate, neck short, often compressed more than body, at 20–30X finely rugulose with more than 20 horizontal ridges in a vertical series or reticulate or cancellate. |
0.75–1 × 0.6–0.85 mm. |
Tubercles | whitish to brown, pyramidal, lower than wide, often 3-lobed as viewed from the top, 0.1–0.3 × 0.4–0.65 mm. |
deltoid, 0.3–0.5 × 0.3–0.5 mm, 3/5 of to as high as wide, 1/3–2/3 as high and 1/2–3/4 as wide as achene. |
2n | = 10. |
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Eleocharis bolanderi |
Eleocharis ovata |
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Phenology | Fruiting late spring–summer. | Fruiting summer–fall. |
Habitat | Fresh, often summer-dry meadows, springs, seeps, stream margins | Fresh, often drying shores, lake and stream beds, bogs, tidal estuaries, disturbed places |
Elevation | 1000–3400 m (3300–11200 ft) | 10–700 m (East), 1500–2000 m (Arizona) (0–2300 ft (East), 4900–6600 ft (Arizona)) |
Distribution |
CA; CO; ID; NV; OR; UT
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AZ; CT; IA; IL; IN; KY; MA; ME; MI; MN; MO; NH; NJ; NY; OH; OK; OR; PA; VA; VT; WA; WI; WV; AB; BC; NB; NL; NS; ON; PE; QC; Eurasia
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Discussion | Eleocharis bolanderi is clearly distinct from E. montevidensis, from which it differs in its dense, tufted habit with short, caudexlike rhizomes, its leaf sheaths without a tooth, its achene and tubercle shapes, and its acute floral scales. Specimens of Eleocharis bolanderi without rhizomes or achenes are easily confused with E. decumbens, which often may be distinguished by culms 0.5–2 mm wide, and spikelets with scales sometimes more than 3 mm long. The tubercles of E. bolanderi are usually poorly developed and much lower than wide; in E. decumbens they are usually well developed and about as high as wide. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Although Eleocharis ovata has often been confused with E. obtusa, B. M. H. Larson and P. M. Catling (1996) showed that these species may be distinguished by non-overlapping widths of the tubercles, at least in Canada. The records of E. ovata in New Brunswick, Newfoundland, Nova Scotia, and Prince Edward Island are based on B. M. H. Larson and P. M. Catling (1996) and the records in Illinois, Indiana, Missouri, Montana, New Jersey, Oregon, and Washington are based on D. M. Hines (1975). Eleocharis ovata probably also occurs in Manitoba and Saskatchewan. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 103. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Eleocharis | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleogenus > ser. Ovatae |
Sibling taxa | ||
Synonyms | E. montevidensis var. bolanderi | Scirpus ovatus, E. obtusa var. ovata, E. ovata var. heuseri |
Name authority | A. Gray: Proc. Amer. Acad. Arts 7: 392. (1868) | (Roth) Roemer & Schultes: in J. J. Roemer et al., Syst. Veg. 2: 152. (1817) |
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